Fuse



April 22, 1952 J, B. MacLEA 2,593,775

FUSE

Filed Aug. 14, 1944 2 Sl-IEETS-ShE-ET 1 INVENTOR. 4 JOHN 5. MAC LEAN ATTORNEY.

April 22, 1952 J. B. MacLEAN 2,593,775

FUSE Filed Aug. 14, 1944 2 SI-lEETS-ShEET 2 II VI! K5? as I" l rlu lunullu w w i% :ITU FITIIFH l l INVENTOR. JOHN B MAC LEAN ATTORNEY.

Patented Apr. 22, 1952 UNITED STATES PATENT OFFICE FUSE J ohn B. MacI-lean; Peru, 111., assignpr to' General" Time Corporation, New York, N. Y., a; corpora-' tion: of Delaware:

Application August l l, 1944,.SerialNo. 549,310

6 Claims. 1.,

This invention relatesin' general to. fiuzesi and more particularly to time'fuzes for rocket bombs orsimilar projectiles; Themainobjectof. theinvention'is to provide animproved'fuze of'thistype having new and novel safety and other features.

According to one feature of the invention; the

timing mechanism is released to start the timing operation as the rocketis fired from its" firing tube;

Another feature. of the invention relates to.the means for normally maintaining. the fuze' safe condition and for. arming same only after the rocket leaves. its tube and" has ceasedacceleration and begun deceleration.

According to a-further feature of the invention, the acceleration of therocket as it' leaves the tube initiates, the tiiningoperation-andsubsequent deceleration of "the rocketiarms. the fuze fordetonation.

A further feature of theinventionmesides in the provision of means for preventingdetonation of .the 'fuzeby the setback force'on the firing-spin as the rocket is fired or by, air pressure on the nose of the fuze set up by-a rocket fired from an adjacent tube and" permitting detonation oflthe fuze upon impact or at the expiration of a predetermined time interval;

The above and other objects and features of the invention not specifically. mentioned and a clear understanding. of the construction and operation of'the .inventionmay. beh'ad from a-perusal of I ment; and; v

Fig. 5 isaperspectiVe. view. of the firing. pin and the release mechanism therefor.

Fig. 61s a detailediviewin elevation of gears 69 and 517.

Fig 7..is.a detailed view inelevation of .gearis and hub. member. .56.

Fig-. .8 is anelevationalview of plate Mltaken on the line B-8 of Fig. 4;

InFig; 1 the fuze" is shown-ready forfattachment'to a-rocket. All. movable parts are in a cocked position.

In'Figs'. 3. and 4-the-inertia movement lSLShOWIl with ,each movab1epart:i1r..;the :position assumed af-ter Lthe-rocket hassdecelerated:

Referring to thedrawing in detail the iuze casing consists essentially of a body portion I- and a head portion 3. The body portion I is provided with a threaded section 2 to enable the fuz e to be screwed into the body of the rocket bomb. The head section 3 includes a reduced projecting portion 4 which is adapted to fit intoa center bore of the body I. Tl iehead'is maintainedin'the body by means of the spring wire 5 which fits-into a groove in the body I. The body I is' also provided with a plurality of' screws; 6"the ends of which lie against thespring wire 5 and these screws 6 may be turned down in order to force the spring'wire 5part way into'a complementary groove in the reduced portion 4 of the head 3. Thus the head'3'is maintained in the body- I but may be easily rotated in order'to set the time of operation of the fuze'a'swillb'e described later;

A thumb screw '1 isalso 'providedhavingits end bearingagainst thespring. wire 5 and this thumb screw I may be'tightened in order to fixedly'attach the head3to body I after the timesetting has been effected; Thec'oil sprin'g8 surrounds the shank of screw I and tends to maintain the screw in its set position. p

The body I is provided with a projecting flange portion 9 having several notches therein, this flanged portion" being adapted to buttup against the end of the rocket bomb when the fuze is inserted therein and the notches being provided to enable the fuze to be screwed into the'bomb with a suitable wrench;

A portion of the head .3- is knurled as at It so that the same maybe more easily grasped to eiiect-thetime-setting. The surface of 'thehead 3 is also provided with the scaleI I which indicates the time ofoperation of the fuze;

Mountedwithin the body I is the timing device 26. This device issecured-to the body. by means of screws SB-and consists of a plurality of plates held togetherby screws (not-shown)-, the-timing movement beinglocated within these plates. Since this timing movement 'forms no part-oi the present invention the samehas not beenshown in detail. It is sufi'icient forthe-purposes of'this explanation to state that the movement'terminates in a rotatable hub which mounts the timing disc 21, the hub and disc rotating at'a predetermined'rate depending upon the desired extent of the timeof operation of the fuze.

Also mounted withina cavity at'the right'end of body I is an inertia movement located on'the plate-4| which in turn is mounted on bosses 39 of the body by means of screws 48; The right hand end of the fuze body is closed by means-of the platettmounting' the closure-cup 45 and the booster cup 44 which is screwed into the body at 45 and contains the explosive booster charge 96.

The head 3 is provided with a center bore through which extends the firing pin 13. The firing pin is provided at its left hand end as viewed in Fig. 1 with the striker M which is screwed to the end of firing pin and held in the proper position by bending over portion of the inner hub of the striker against a slabbed portion of the firing pin as shown at [6. The striker is provided with a cylindrical extension l5 which slides into the hole 29 formed in the cylindrical portion l2 of the head assembly. A further hole 2! is provided to accommodate the firing pin sleeve or cup 23 which retains one end of the firing pin spring 22, the other end of which bears against the shoulder formed at the left hand end of hole 2| as shown in Fig. 1.

The firing pin [3 is provided with an enlarged portion 24 and the firing pin spring cup 23 bears against this enlarged portion in order to bias the firing pin to the right as viewed in Fig. 1 and to force same to firing position when the cup is released as will be explained later.

'The cup 23 is held in its left hand position with the spring 22 under compression by means of the cooking pin 25 having a slabbed portion in engagement with cup 23. Secured in the cocking pin 25 is the cocking pin screw 3! which extends from the right hand end of head assembly 3, the latter being provided with a slot for movement of the cocking pin screw to allow the cocking pin 25 to rotate and release the cup 23.

Mounted on the right hand surface of the hub 4 of the head assembly 3 is a firing lever 28 which is rotatably. held to the head by means of screw 29 and is provided with a hook portion 33 adapted to engage the cooking pin screw 3 I. This firing lever is provided at its other end with a projection 32 which is engaged by the lateral projection'33 of.the timing disc lever 34 which in turn is rotatably mounted to the head assembly by means of screw 35. The timing disc lever 34 terminates at its opposite end in the laterally extending projection 33 which is adapted to engage the periphery of the timing disc 21. The arrangement of the firing pin, cocking pin, timing disc and control levers is clearly disclosed in Fig. 5 of the drawing.

The timing disc 21 is provided with a notch 31 and the projection 36 of the lever 34 drops into this notch to release the firing pin after the predetermined set time interval. Extending through the timing movement 26 and into the notch 31 is the arming pin 46. This arming pin normally holds the timing disc in its zero position with the time movement in energized condition and is moved to the right (as seen in Fig. 1 by means of the arming pin spring 4! in order to start the timing of the interval during which the detonation of the fuze is delayed.

Referring now more particularly to Figs. 3 and 4 of the drawing the inertia movement comprises parallel spaced plates 48 and 49 which are held in spaced relationship by means of the lateral plates 59 and 5|. Plates 48 and 49 have extending projections which fit into notches in the mounting plate 4|, the edges of these projections being bent over in order to securely hold the movement to the mounting plate. movement consists essentially of an escape wheel. 69 which is rotatably mounted on a stub shaft 61 secured to plate 49. Riveted to the outer surface of this escape wheel is the inertia weight 10. Also secured to the escape wheel and rotatable therewith is the pinion 17. Mounted on a The inertia second stub shaft 15 is the governor or pallet 14 which is provided with the two pallet pins 16 adapted to engage the teeth of the escape wheel 69. The pinion H is in engagement with the gear wheel 59 fixedly mounted on shaft 55 which has its hearings in the two plates 48 and 49. Fixed to the gear wheel 59 is the hub or cam member 56 which controls the release pin 60 to be described later. Also mounted on shaft 55 between the plates 48 and 49 is an assembly comprising a hub portion 52 and. the two segment gears 53 and 54. This assembly is rotatably mounted on shaft 55 so that gear wheel 59 may be rotated without moving said assembly.

Extending from plate 49 is an arm or bracket 72 to which is secured one end of the coil spring 13. This spring 13 is coiled around the shaft 61 and the other end of the spring is in engagement with the inertia weight 10 as seen in Fig. 3. The split washer 68 engages a groove on the end of shaft -61 in order toretain the spring in position. Thus the escape wheel 69 is biased for clockwise rotation by means of the spring 13.

Acylindrical tube extends between plates 59 and 51 and provides passage for the firing pin'through the inertia movement device. The gear segments 53 and 54 extend through slots in plate 5| and the teeth of these segments engage rack teeth 19 provided on the detonator slider 42 as shown in Fig. 2 of the drawing. The toothed portion of gear segment 53 extends around approximately two-thirds of its periphery while the other portion of gear segment 54 (as shown in Figure 1) extends around approximately one-fourth of its periphery. The gear segments 53 and 54 are positioned on shaft 55 so that the teeth of both segments engage the rack teeth 19 to start movement of the detonator slider. When the slider has been moved a short distance the teeth of segment 54 are disengaged, but the teeth of segment 53 are still engaged and drive the slider to the end of its travel. The detonator slider 42 mounts the detonator 84 and is arranged to move between plates 48 and 49, carrying the detonator to a position in line with the firing pin. The release pin 60 extends through the two gear segments 53 and 54. through the semi-circular slot 66 in plate 49, and into engagement with the control hub or cam 53. The semi-circular slot 66 permits the pin 60 to be turned through approximately The release pin is biased to the left (as seen in Fig. 4) by means of a spring 6|, one end of which bears against the segment gear 54 and the other end of which bears against a collar on the release pin.

As seen in Fig. 4 the control hub 56 has a notch 51 transverse of its peripheral edge, this notch or slot being directly in line with a hole in the gear 59. The control hub 56 is also provided with a further cutaway portion 58 which connects with the slot of notch 51 but does not extend all the way across the peripheral face of the hub.

In order to prepare the inertia movement for operation, the escape wheel 69 is rotated in a counter clockwise direction about a turn and a quarter which turns gear 59 about one-half turn until the hole 1| therein is in register with the hole in gear 59 and the release pin 60. A pointed instrument may then be inserted through these holes in the escape wheel 69 and gear 59 into engagement with the end of release pin 60 moving the release pin to the right as seen in Fig. 4 until it is in line with the cutaway portion 58. The escape wheel 69 may then be released and will be a rotated: in; a. clockwise. direction: until stopped z'tby' the engagement. .of pin. 6|] 3 with the wall ,surface.;-of:1the. cutaway portion: 58 of icon-1 trol; hub 56; Inr..this -position :thesreleaserpin 6 :extends through plate 548 .iand engages .hole in'aone .:end..of:an.arming 'pin lever .81 .as .clearly shown' in Figs." 1" and :22. of..= the edrawingsr. This arming; pin :,lever: 8| is. rotatably mounted on plate :48' by 'means .of the screw... -83';. The: other end iof1zthe. arming pin levergis ;bent; at an: angle to form the projection82 against :which; lies :the end :of :the arming pin" 46.

The plate M has ar-bracket 1B3 bent uprataright angles thereto and. this :bracket -mounts: auhub lawwhich-is provided with internal screwgthreads. Gear: 59 :hasa; second hole :therein which; is adapted to beengaged; by the :end 89 ofra wlock pin :81' which is inserted through-a.hole in-the wall of -the-body l andissprovided with SOI'W= threads which-screwintothe hub 18;; The outer end of the lock. pin-81 iiS.,bnt"at anzangleqand provided :witha hole :88 adapted to :receivea--wire so that the pin may be-sealed- 'in-the fuze:during transportation and-before the fuze is readyyfor assemblyin ,the rocket bomb; This lock; pin is an additional safety-:feature to insure-that there will be no inadvertent arming of'therfuze during handling;

The left hand end of the head assembly 3 is provided with a thin. metal 'cover l8 held in position by a rib which fits into a groove in the head as shown at I9. A striker retainer plate I1 is provided which rests on the end of the head section 3' and-against'which bears the striker l4. This striker retainer TiS'DlOVldGd so that the firing-piniwill not be moved tofiring position by the iset-jback force as the rocket bomb leaves :the firingtube. The striker. cover, l8 is-provided to prevent the air pressure from firing thefuze when a rocket bomb is fired from an adjacent tube.

Referring now to the operation and use of the fuze as described in this application, when it is desired to mount the fuze in a rocket bomb the lock pin 81 is removed and the fuze is secured into the bomb as previously explained. The thumb screw 1 is then loosened and the head 3 is turned until the desired firing time interval is indicated on the scale II. The thumb screw 1 is then tightened so that the head 3 and body I will be securely held together. This fuze is mounted on the nose of the rocket bomb and as the bomb is fired the fuze moves in a direction to the left as seen in Fig. 1. The inertia movement is so mounted within the fuze body that as the bomb leaves the firing tube the inertia movement travels in a direction toward the bottom of the sheet as it is positioned in Fig. 3. The terrific acceleration of the bomb and fuze causes the inertia weight to rotate the escape wheel 69 in a counter clockwise direction. This rotation of the escape wheel and the corresponding rotation of gear 59 in a clockwise direction moves the control hub 56 so that the release pin 60 leaves the cutaway. portion 58 and enters the notch 51. Since the release pin 60 is now free to move to the left as shown in Fig. 4 it is moved in this direction by means of the springs 6!, thereby withdrawing the end of the release pin from the hole in the. arming pin lever 8|.

Referring to Fig. 1, when the arming lever pin 8| is freed by the release pin 60 the arming pin 46 moves to the right under power of the spring 41 thereby withdrawing the left hand end ofthe arming pin from the notch-.inthe timing disc 31. This initiates the operationof the rtiming :devices-andjme timingrdisc .2 ljis :-.ro--

than. the set-back; force -1 on the inertia weight UH], the spring rotates theuescapewwheel in;,a

clockwise direction-which;through. pinion J1 rotates: gear. wheel 59 -and-;shaft= in 'a counter ingengagement with ;the: rack. teeth 19' on ,the detenetor slider 42.? Thus -,the;s1ider -;42 is :moved to. armed ;:,position::b'y the inertia movement '1 and carriesgth'e '1 detonator 84 into the ;-path; of the firingcpin. l 3 and inrline with the closure :cup:85. At an expiration; of: the ;;settime interval. the projection :36 of the ttimingrdisc' lever ;34 idrops intogthernotch 3lfof jthewtiming; disc 12]. Projec-e tion'33 therebyreleases projection 32 of thefiring, l'ever;28 which in turn :rotates -so that; the.,;hook 30 releasesthe cockingpinyscrew- 3i. This @frees the rocking; pin "2 5 so :that it can *rotate. and; allow the :firing; "pin springr cup-23 to-;pass;the slabbed portion. 10E :thescockingtpin; 25:; Thus the :firi-ng .pinqis :1 moved to the: rightby the; spring: 22

detonating 1the fuze; which in; turn brings about the firing 'of the bomb; The a-power-of ,springrlz is sufficient 'to move "the: firing pinv to ;-the right as viewed in .Fig. .1; even.:-.th ough the retainerrplate I7 is still inplace; Aszpreviouslystated the plate back on the striker and firing pin from detonating the fuze and further means are provided to prevent air pressure which may be exerted upon the end of the fuze when a rocket is fired from an adjacent tube from operating the firing pin to detonate the fuze.

These and the other features of the invention might be incorporated in various forms or modifications of the construction shown herein, but such modifications are intended to be covered by the present invention.

What is thought to be new and is desired to have protected by Letters Patent is set forth in the appended claims.

What is claimed is:

1. In a fuze for a rocket bomb, the combination of a firing pin normally tensioned toward a detonator, a normally energized timing device,

a cam disc controlled thereby, means controlled by said cam disc for effecting release of said firing pin, an arming pin normally blocking said cam disc, and an inertia device movable by the acceleration of said bomb as it is fired from its tube for controlling the removal of said arming pin from blocking position to initiate the operation, of said timing device. 7 2. In a fuze for a rocket bomb, the combination of a firing pin normally tensioned toward firin position, a timing device for releasing said firing pin, a detonator slider normally held in safe po sition, and a device including a, spring biased inertia member movable in one direction against said bias by the acceleration of the bomb to control the initiation of the operation of said timing device and a spring biasing said member for movement in the opposite direction upon deceleration of the bomb to move said detonator slider to armed position.

3. In a fuze for a rocket bomb, the combination of a firing pin normally tensioned toward firing position, a spring driven timing device, a cam disc controlled thereby, means controlled by said cam disc for efiecting release of said firing pin, an arming pin normally blocking said cam disc, a detonator slider normally held in safe position and a device including a spring biased inertia member movable in one direction bythe acceleration of the bomb for controlling the removal of said arm-' ing pin from blocking position to initiate the operation of said timing device and a spring biasing said member for movement in the opposite direction upon deceleration of the bomb to move said detonator slider to armed position.

4. In a fuse for a rocket bomb, the combination of a firing pin normally tensioned toward firing position, detonator carrying means normally held in safe position, a, timing mechanism including a rotatable member for controlling release of said firing pin, means blocking the rotation of said member, spring biased inertia means movable against said bias by acceleration of the rocket as it is propelled from its firing tube for controlling the withdrawal of said blocking means to initiate the operation of said timing mechanism, and means controlled by the movement of said inertia means under the influence of the spring bias upon deceleration of the rocket for moving said detonator carrying means to armed position.

5. In a fuze for a rocket bomb, the combination of a firing pin normally tensioned toward firing position, a time movement for controlling release thereof, a detonator slider normally held in safe position, a spring biased inertia member, means actuated by movement of said member against the spring bias by acceleration of the rocket to start said time movement and means actuated by movement of said member in the opposite direction for thereafter moving said detonator slider to armed position.

6. In a fuze for a rocket bomb, the combination of a firing pin normally tensioned toward firing position, a detonator and carrying means therefor normally held in safe position with said detonator out of the path of movement of said firing pin, a spring biased inertia member movable in one direction against the spring bias by the acceleration of the rocket as it is propelled from its firing tube and movable in the opposite direction by the spring upon subsequent deceleration of said rocket, means controlled by the movement of said inertia member by acceleration for releasing said firing pin and means actuated by the movementofsaid inertia member upon deceleration for moving said detonator carrying means to armed position.

JOHN B. MACLEAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,665,666 Junghans Apr. 10, 1928 2,014,393 Mathsen Sept. 17, 1935 2,089,243 Zornig Aug. 10, 1937 2,094,032 Zornig Sept. 28, 1937 

